1. Field of the Invention
The present invention is for a drywall sanding implement and an abrasive pad for use with the same. The drywall sanding implement has particular utility for smoothing joints in drywall construction.
2. Background Information
Sanding poles are frequently used for smoothing joints in drywall construction. During construction, the joints between the panels of drywall are filled with joint compound. The joint compound is allowed to dry, and then abraded with sandpaper to achieve a smooth wall surface. A sanding pole allows the user to sand joints from floor to ceiling level without the need for stepladders or other devices to reach the upper portions of the joints. Such sanding poles typically employ sandpaper mounted to a planar member, which in turn is mounted to one end of a shaft by means of a universal joint. The universal joint allows the planar member to pivot relative to the shaft in two orthogonal planes. Examples of such devices appear to be taught in U.S. Pat. Nos. 4,516,361; 4,848,037; and 4,885,876.
One problem with such devices is that the long shaft is unwieldy, making sanding in tight areas difficult. The '037 patent appears to teach interchangeable pole and hand mountings for the planar member, the hand mounting allowing for hand sanding in tight areas. However, such interchangeability requires complicated structure and appears to be prone to breakage under heavy usage.
A problem with all such devices is the use of sandpaper. When used for smoothing drywall joints, sandpaper quickly loses its abrasive capability, and is prone to tearing on electrical junction boxes or other protrusions from the drywall surface. The effort required to replace the sandpaper is often considerable, since it is typically retained on the planar member by some sort of clamping means.
As an alternative to sandpaper, abrasive sponges have been developed to provide longer lasting abrasive capability. U.S. Pat. No. 4,263,677 appears to teach the use of an abrasive sponge incorporated into a mitt for smoothing drywall joints. While abrasive sponges generally retain their abrasive capacity longer than sandpaper, the shape of such sponges does not allow them to be mounted to conventional sanding poles to allow the user greater reach.
Additionally, when abrasive sponges are used for smoothing drywall joints, they frequently result in scarring, particularly when used in corners. The sponges typically have a parallelogram-shaped cross section, which is generally rectangular. Because the abrasive coating tends to stiffen the sponge. When one side of the sponge is used to sand a joint, the center of the side deforms more than the edges, since the edges are stiffened by the abrasive coating on the adjacent sides. Thus, the edge which is distant from the corner tends to resist deformation, and abrades a scar parallel to the corner as the joint is sanded.
Thus, there is a need for a sanding pole which can incorporate the advantages of sponge-type abrasive articles, and which allows for rapid transition between pole-type sanding and hand sanding. There is also a need for a sponge-type abrasive article which can be used to sand corners without risk of scarring.